AḤMAD B. ʿABDALLĀH B. MAYMŪN AL-QADDĀḤ (3rd/9th century), son of the supposed founder of Ismaʿili doctrine (see ʿAbdallāh b. Maymūn al-Qaddāḥ) and grandfather of the first Fatimid caliph, Mahdī. Anti-Ismaʿili writers assert his descent from the alleged heretic “Maymūn al-Qaddāḥ,” but this claim is as unhistorical as the official Fatimid account that he was a grandson of Moḥammad b. Esmāʿīl b. Jaʿfar al-Ṣādeq. Aḥmad’s place in Fatimid genealogy is indicated by a letter of Mahdī to the Ismaʿilis of Yemen (H. F. Hamdani, On the Genealogy of Fatimid Caliphs, Cairo, 1958, Arabic text, p. 11, bottom) and by the account of Aḵū Moḥsen (cited in Ebn al-Dawādārī, Kanz al-dorar, ed. Ṣ. al-Monaǰǰed, VI, Cairo, 1961, pp. 17ff.; Maqrīzī, Etteʿāẓ al-ḥonafāʾ, ed. J. Šayyāl, I, Cairo, 1387/1967, pp. 22ff.; cf. Fehrest [Tehran1], p. 238).

Little is known of Aḥmad’s life. He succeeded his father as second head (ḥoǰǰa) of the Ismaʿili mission (daʿwa) and, like him, lived as a merchant in Salamīya in Syria. In 261/874-75 (according to Ebn al-Nadīm) or 264/877-78 (Aḵū Moḥsen) he sent the missionary (dāʿī) Ḥosayn Ahwāzī to the district (sawād) of Kūfa. The latter converted Ḥamdān Qarmaṭ and founded the “Qarmatian” sect of Iraq (Ebn al-Dawādārī, op. cit., VI, pp. 19, 46). The dispatch of the dāʿīs Ebn Ḥawšab Manṣūr al-Yaman and ʿAlī b. al-Fażl to Yemen in 267/881 may have occurred already in his lifetime (Qāżī Noʿmān, Eftetāḥ al-daʿwa, ed. W. al-Qāżī, Beirut, 1970, pp. 39, 44). Aḵū Moḥsen claimed that Aḥmad also directed Abū ʿAbdallāh Šīʿī to the Maḡreb in 279/892-93 and so laid the foundation for later Fatimid power there (Ebn al-Dawādārī, op. cit., VI, p. 20).

Fatimid tradition reports secret journeys of Aḥmad to Kūfa and Daylam or to ʿAskar Mokram in Ḵūzestān, his father’s home (Edrīs, ʿOyūn al-aḵbār, ed. M. Ḡāleb, IV, Beirut, 1973, p. 394). It also makes him the author of the Rasāʾel eḵwān al-ṣafāʾ (ibid., IV, pp. 367ff.), although these texts evidently were first received by the Ismaʿilis in the 5th/11th century. Aḥmad died at an unknown date in Salamīya; his son Moḥammad Abu’l-Šalaʿlaʿ, uncle of the later caliph Mahdī, succeeded him as director of the daʿwa.

Bibliography: Given in the text.

(H. Halm)

Originally Published: December 15, 1984

Last Updated: July 28, 2011

This article is available in print.
Vol. I, Fasc. 6, pp. 638-639

Cite this entry:

H. Halm, “AḤMAD B. ʿABDALLĀH,” Encyclopædia Iranica, I/6, pp. 638-639; an updated version is available online at http://www.iranicaonline.org/articles/ahmad-b-1 (accessed on 16 March 2014).